In the late 1990s the technique of expansion of tubulars started to become widely used downhole. There were several applications such as casing patches, screen expansions in lieu of gravel packing, and expansion of casing or slotted liners as part of well completion. Different mechanical swages were devised that could be pushed or pulled through tubulars. These swages were of the fixed dimension variety or incorporated rollers that had the ability to extend or retract. Another technique that was developed utilized inflatable bladders to perform the expansion.
While these techniques were effective, they had drawbacks. Mechanical swages could get stuck before the expansion was complete and were problematic to use if there was any significant deviation in the wellbore. Rigid tubing was necessary in order to be able to transmit significant pulling forces from the surface to the swage. The inflatables proved costly to run and, due to their complexity, occasionally failed to inflate or burst due to well conditions during run in or when in position for inflation. The nature of inflatables limited the available expansion force due to the pressure rating of the inflatable. What was needed was a simpler technique that could expand a tubular downhole that did not have the limitations of the known techniques described above.
Cup type seals have been in oilfield use for a long time. They have, among other things, been used to pressure test tubulars for pinhole leaks or fractures. One such device is illustrated in U.S. Pat. No. 4,149,566 in its FIG. 5. It describes the test rig involving a mandrel with opposed test cups to isolate the zone to be pressure tested with fluid to be delivered between the cups. This reference describes the limited reliability of predecessor test cups to withstand the rigors of testing thousands of feet of tubulars and the need for frequent cup replacements.
Yet, despite the use of test cups for pressure testing tubing being known since the 1970s and the rapid commercialization of the expansion of tubulars downhole in the late 1990s, there has heretofore been no known device that incorporates the use of cup type seal elements in a device to expand tubulars. The present invention allows, among other applications, the insertion of cladding into existing casing and expanding it into a sealed engagement with existing casing. In the context of this application “cladding” comprises, among other things, a sleeve or a scroll that stays expanded due to a ratchet or other device, casing or tubing. It can also be used to expand casing or tubing. Depending on the mounting of the cup seals, the tool can be repositioned to sequentially expand long lengths of cladding, casing or tubing. These and other advantages will be more apparent to those skilled in the art from a review of the description of the preferred embodiment and the claims below.
Also related to cladding expansion are U.S. Pat. Nos. 2,812,025 (showing expansion of a scroll downhole), 4,099,563 and 5,803,177(showing packer cups used in a downhole tool).